Air bag type gravity compressed air energy storage system

Abstract

The invention discloses an air bag type gravity compressed air energy storage system and belongs to the technical field of air energy storage. The energy storage system is installed in a vertical shaft, the energy storage system comprises a bearing frame, a gravity module, an air storage bag and an air balancing device, the bearing frame is horizontally arranged in the vertical shaft and divides the vertical shaft into an upper area and a lower area, the gravity module is placed on the bearing frame, and the air storage bag is placed in the area below the bearing frame. The gas balancing device is mounted at the bottom of the shaft and communicated with the bottom of the gas storage bag; the vertical shaft is divided into the gravity area and the gas storage area through the bearing frame, a proper gravity module can be matched according to needs, the overall size is greatly reduced, the maintenance cost is reduced, the abandoned vertical shaft in the mining area can be used after being transformed, and large-scale popularization is facilitated; the gas storage bag is used for storing gas, the processed gas storage bag is directly placed at the bottom of the vertical shaft and connected with a gas balancing device for use, installation and replacement are convenient, and the inner wall of the vertical shaft does not need to be greatly modified.

Description

Technical Field

[0001] The present invention belongs to the technical field of air energy storage, and in particular relates to an airbag-type gravity-compressed air energy storage system. Background Art

[0002] Compressed air energy storage, as a large-scale, clean physical energy storage technology, has great potential for supporting the safe operation of power grids and promoting the absorption of renewable energy. Compressed air energy storage systems achieve zero-carbon, large-scale energy storage by decoupling and recoupling the thermal energy and potential energy of compressed air. By switching back and forth between compressor unit energy storage and turbine unit power generation modes, they can provide the power grid with auxiliary services such as peak shaving, frequency regulation, black start, and reactive power compensation. This alleviates the pressure of dynamic load regulation on traditional generator sets and provides fluctuation smoothing and grid-connected services for renewable energy generators to absorb and absorb wind and solar power curtailment. Compared with pumped hydro storage, it has a shorter construction period, greater applicability, and greater flexibility; compared with other new energy storage technologies, it has more mature technology, larger scale, and requires less investment.

[0003] Gravity compressed air energy storage (GCAS) has emerged to address the current problems of compressed air energy storage technology, which relies on large air storage chambers, has limited application sites, and has low energy density. The basic principle of gravity compressed air energy storage is as follows: during periods of low electricity demand, air is compressed to high pressure by a compressor unit and stored in the air storage chamber, converting electrical energy into compressed air potential energy. During peak electricity demand, the high-pressure air is heated and enters an expander, becoming atmospheric air. This process drives the generator to generate electricity, converting the air compression potential energy into electrical output. The air pressure in the air storage chamber remains constant throughout the entire process. Gravity compressed air energy storage offers the advantages of high compressed air energy density and flexible layout. Its features include: constant air storage chamber pressure, high expander efficiency, and high energy storage density of the compressed air in the air storage chamber. The air storage chamber volume is significantly reduced, approximately 15% of that of conventional compressed air energy storage power stations, allowing for flexible layout and unrestricted by terrain. Compared to stand-alone gravity energy storage, the weight and size of the compacts are significantly reduced.

[0004] Document number CN115224808A discloses a gravity-compressed air energy storage system based on an adjustable gravity block. The system includes a sealing membrane that is sealed to the outer wall of a gravity assembly and the inner wall of a shaft, so that the sealing membrane, the space below the shaft, and the gravity assembly form an air storage chamber. During energy storage, electrical energy drives an air compressor unit, which introduces compressed air into the air storage chamber. The pressure of the compressed air pushes the gravity assembly upward. During energy release, the compressed air in the air storage chamber is introduced into an air expansion unit, driving the air expansion unit to generate electricity. The problems with this energy storage device are: 1. The pressure-bearing cylinder device connected to the sealing membrane is bulky, which brings about a large engineering investment in actual projects and is not economical; 2. During the energy storage and release process, the gravity component reciprocates in the shaft, and the sealing membrane moves axially therewith under tension, which can easily get stuck and torn in the gap between the outer wall of the gravity component and the inner wall of the shaft, and the sealing membrane is easily damaged; 3. The connection between the sealing membrane and the outer wall of the gravity component and the inner wall of the shaft is subject to shear stress under the action of the gravity component and the megapascal high-pressure gas. The strength requirements of the thin-walled sealing membrane are extremely high, and special materials need to be developed; 4. The connection between the sealing membrane and the outer wall of the gravity component and the inner wall of the shaft is difficult; 5. The gravity component (pressure-bearing cylinder) is not equipped with a side guide device. When the gravity component reciprocates in the shaft, it is prone to overturning accidents.

[0005] Document No. CN115208070A discloses a gravity block assembly and gravity compressed air energy storage system designed to protect against impact loads, including a sealing membrane. This energy storage device has the following problems: 1. The pressure-bearing cylinder connected to the sealing membrane is bulky, resulting in significant engineering investment and poor economic efficiency. 2. During energy storage and release, the gravity assembly reciprocates within the shaft, and the sealing membrane, under tension, moves axially with it. This can easily cause the sealing membrane to become stuck or torn in the gap between the outer wall of the gravity assembly and the inner wall of the shaft, resulting in damage. 3. The connection between the sealing membrane, the outer wall of the gravity assembly, and the inner wall of the shaft is subject to shear stress from the gravity assembly and the megapascal-level high-pressure gas. This thin-walled sealing membrane requires extremely high strength, necessitating the development of specialized materials. 3. The sealing membrane is difficult to connect to the outer wall of the gravity assembly and the inner wall of the shaft. 4. The gravity assembly (pressure-bearing cylinder) is equipped with a guide device, but during energy storage, the gravity assembly is in an upward motion, and the sealing membrane can easily interfere with the guide device, causing accidents.

[0006] Among the aforementioned achievements, there are still unresolved issues regarding the sealing membrane's material quality, anchoring, and axial stability of the pressure-bearing cylinder, all of which require urgent solutions. This report proposes a pressure-compensated, oil-lubricated seal structure that is expected to replace the sealing membrane structure and address these issues. Summary of the Invention

[0007] The present invention aims to solve the problems existing in the existing compressed air energy storage system and provides an airbag-type gravity compressed air energy storage system.

[0008] The airbag-type gravity compressed air energy storage system of the present invention is installed in a vertical shaft and is characterized in that the energy storage system includes a supporting frame, a gravity module, an air storage bag, and a gas equalization device. The supporting frame is horizontally arranged in the vertical shaft, dividing the vertical shaft into upper and lower areas. The gravity module is placed on the supporting frame, and the air storage bag is placed in the area below the supporting frame. The gas equalization device is installed at the bottom of the vertical shaft and is connected to the bottom of the air storage bag. The load-bearing frame includes a pressure-bearing steel plate, a guide device, and a steel lining. The steel lining is vertically arranged on the inner wall of the shaft, and the pressure-bearing steel plate is horizontally arranged inside the shaft. Guide devices are symmetrically provided at both ends of the pressure-bearing steel plate. The guide devices are in contact with the steel lining, and the pressure-bearing steel plate slides along the steel lining through the guide devices. The edge of the airbag is S-shaped, with the top fixedly connected to the bottom of the carrier frame and the bottom fixedly connected to the bottom of the shaft. During handling, the volume of the airbag is reduced for easy transportation. When gas is injected, the folds open to form the airbag wall. When gas is released, the outer wall of the airbag folds along the folds. The gas balancing device includes a connecting pipe, an air inlet valve, an air outlet valve, a collecting ball shell and a ventilation branch pipe. The connecting pipe is horizontally arranged at the bottom of the vertical shaft. The air inlet valve and the air outlet valve are respectively installed at both ends of the connecting pipe, and the collecting ball shell is installed in the middle of the connecting pipe; several ventilation branches are installed on the collecting ball shell in a circular manner at one end, and the other end is connected to the bottom of the air storage bag. The collecting ball shell is connected to the air storage bag through the ventilation branch pipe.

[0009] The gravity module includes a gravity block, a steel frame and a guide device. The steel frame is arranged on the upper part of the load-bearing frame. The gravity blocks are stacked sequentially in the steel frame. The array guide devices are installed on the outer wall of the steel frame from top to bottom. Each group of guide devices has at least two and is symmetrically arranged. The guide device is in contact with the steel lining, and the steel frame slides along the steel lining through the guide device.

[0010] The top of the steel liner is provided with a limiting block and a limiting steel beam. The limiting steel beam is fixed on the top of the steel frame. The limiting block is arranged above the limiting steel beam to prevent the steel frame from sliding out and falling off, causing damage to the equipment.

[0011] The guide device includes a frame, an elastic pad, a rotating frame, a guide wheel, a hinge shaft and a support. The frame is fixed to the pressure-bearing steel plate or the outer wall of the steel frame. The support and the elastic pad are respectively installed on both sides of the frame. One end of the rotating frame is fixed to the elastic pad by bolts, and the other end is connected to the support by a hinge shaft; the guide wheel is installed on the rotating frame, the outer edge of the guide wheel is higher than the outer edge of the rotating frame, and the outer edge of the guide wheel is in contact with the steel lining.

[0012] Auxiliary sealing strips are also provided on both sides of the load-bearing frame. The auxiliary sealing strips include a base plate, a pressure plate, a sealing rubber, a retaining frame, a friction-reducing layer, a cavity and an anti-deflection boss, which are basically fixed on the bottom side wall of the load-bearing frame. The sealing rubber is L-shaped, and an L-shaped retaining frame is buried inside. The vertical edge of the sealing rubber is fixed to the lower part of the edge of the base plate, and the top of the horizontal edge is in contact with the steel lining. The top of the horizontal edge is plated with an anti-friction layer; the cover plate covers the vertical edge of the sealing rubber and is basically connected and fixed; there is a cavity between the bending part of the sealing rubber and the cover plate, and the cavity provides storage space for the sealing rubber when it is deformed to prevent the sealing rubber from damaging the cover plate; a protrusion is provided at the lower edge of the cover plate, which is an anti-deflection boss. When the load-bearing frame slides downward, the sealing rubber is deformed upward due to friction, and the anti-deflection boss limits the deformation to prevent the load-bearing frame from deflecting.

[0013] The outer edge of the steel lining is also provided with a buffer, which is located below the edge of the limiting steel beam and is fixed on the wall platform extending from the steel lining. The buffer includes an outer shell, an air spring, a fixed block and a slide groove. The air spring is fixed on the top of the wall platform, and the outer shell covers the air spring. A slide groove is provided in the wall below the outer wall of the outer shell, and the fixed block is fixed on the outside of the outer shell. When the upper limiting steel beam descends, the limiting steel beam is pressed on the top of the outer shell. After the outer shell is subjected to force, it slides into the slide groove, and the internal air spring bears the pressure to provide buffering.

[0014] The airbag-type gravity compressed air energy storage system of the present invention utilizes a carrying frame to divide the vertical shaft into a gravity area and a gas storage area. It can be equipped with suitable gravity modules as needed, which greatly reduces the overall size and reduces maintenance costs. It can be used after modifying abandoned mining vertical shafts, which is conducive to large-scale promotion. The airbag is used for gas storage. The processed airbag is directly placed at the bottom of the vertical shaft and connected to a gas balancing device for use. It is easy to install and replace, and there is no need for extensive modifications to the inner wall of the vertical shaft. At the same time, mass production of airbags can also greatly reduce the processing cost of the airbags and reduce replacement costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention.

[0016] Figure 2 This is a schematic diagram of the deployment of the air storage bag of the present invention.

[0017] Figure 3 Schematic diagram of the airbag structure.

[0018] Figure 4 Schematic diagram of the load-bearing frame structure.

[0019] Figure 5 Schematic diagram of the gravity module structure.

[0020] Figure 6 Schematic diagram of the guide device structure.

[0021] Figure 7 Schematic diagram of the gas balancing device structure.

[0022] Figure 8 Schematic diagram of the buffer structure.

[0023] Figure 9 Schematic diagram of the buffer pressure.

[0024] Figure 10 Schematic diagram of the auxiliary sealing strip structure.

[0025] In the figure, the air storage bag 1, the load-bearing frame 2, the gravity module 3, the shaft 4, the steel lining 5, the limiting steel beam 6, the limiting block 7, the buffer 8, the gas balancing device 9, the intake valve 10, the exhaust valve 11, the air storage bag 12, the pressure-bearing steel plate 13, the guide device 14, the auxiliary sealing strip 15, the gravity block 16, the steel frame 17, the limiting steel beam 18, the support 19, the hinge shaft 20, the guide wheel 21, the rotating frame 22, the elastic pad 23, the frame 24, the connecting pipe 25, the collecting ball shell 26, the ventilation branch pipe 27, the air spring 28, the outer shell 29, the fixing block 30, the slide groove 31, the base plate 32, the pressure plate 33, the sealing rubber 34, the retaining frame 35, the friction-reducing layer 36, the cavity 37, and the anti-deflection boss 38. DETAILED DESCRIPTION

[0026] Example 1: An airbag-type gravity compressed air energy storage system, installed in a vertical shaft, includes a supporting frame, a gravity module, an air bag, and a gas equalization device. The supporting frame is horizontally arranged in the vertical shaft, dividing the vertical shaft into upper and lower areas. The gravity module is placed on the supporting frame, and the air bag is placed in the area below the supporting frame. The gas equalization device is installed at the bottom of the vertical shaft and is connected to the bottom of the air bag. The load-bearing frame includes a pressure-bearing steel plate, a guide device, and a steel lining. The steel lining is vertically arranged on the inner wall of the shaft, and the pressure-bearing steel plate is horizontally arranged inside the shaft. Guide devices are symmetrically provided at both ends of the pressure-bearing steel plate. The guide devices are in contact with the steel lining, and the pressure-bearing steel plate slides along the steel lining through the guide devices. The edge of the airbag is S-shaped folded, with the top fixedly connected to the bottom of the carrier frame and the bottom fixedly connected to the bottom of the shaft. During transportation, the volume of the airbag is reduced to facilitate transportation; when gas is injected, the folds open to form the airbag wall; when gas is released, the outer wall of the airbag folds according to the folds; The gas balancing device includes a connecting pipe, an air inlet valve, an air outlet valve, a collecting ball shell and a ventilation branch pipe. The connecting pipe is horizontally arranged at the bottom of the vertical shaft. The air inlet valve and the air outlet valve are respectively installed at both ends of the connecting pipe, and the collecting ball shell is installed in the middle of the connecting pipe; several ventilation branches are installed on the collecting ball shell in a circular manner at one end, and the other end is connected to the bottom of the air storage bag. The collecting ball shell is connected to the air storage bag through the ventilation branch pipe.

[0027] The gravity module includes a gravity block, a steel frame and a guide device. The steel frame is arranged on the upper part of the load-bearing frame. The gravity blocks are stacked sequentially in the steel frame. The array guide devices are installed on the outer wall of the steel frame from top to bottom. Each group of guide devices has at least two and are symmetrically arranged. The guide devices are in contact with the steel lining, and the steel frame slides along the steel lining through the guide devices.

[0028] Limit blocks and limit steel beams are set on the top of the steel lining. The limit steel beams are fixed on the top of the steel frame, and the limit blocks are set above the limit steel beams to prevent the steel frame from sliding out and falling off, causing damage to the equipment.

[0029] The guide device includes a frame, an elastic pad, a rotating frame, a guide wheel, a hinge shaft and a support. The frame is fixed to the pressure-bearing steel plate or the outer wall of the steel frame. The support and the elastic pad are respectively installed on both sides of the frame. The elastic pad is a rubber pad. One end of the rotating frame is fixed to the elastic pad by bolts, and the other end is connected to the support by a hinge shaft. The guide wheel is installed on the rotating frame, the outer edge of the guide wheel is higher than the outer edge of the rotating frame, and the outer edge of the guide wheel is in contact with the steel lining.

[0030] Auxiliary sealing strips are also provided on both sides of the load-bearing frame. The auxiliary sealing strips include a base plate, a pressure plate, a sealing rubber, a retaining frame, a friction-reducing layer, a cavity and an anti-deflection boss. They are basically fixed on the bottom side wall of the load-bearing frame. The sealing rubber is L-shaped, and an L-shaped retaining frame is buried inside. The vertical edge of the sealing rubber is fixed to the lower edge of the base plate, and the top of the horizontal edge is in contact with the steel lining. The top of the horizontal edge is plated with polytetrafluoroethylene as a friction-reducing layer; the cover plate covers the vertical edge of the sealing rubber and is basically connected and fixed; there is a cavity between the bending part of the sealing rubber and the cover plate, and the cavity provides storage space for the sealing rubber when it is deformed to prevent the sealing rubber from damaging the cover plate; a protrusion is provided at the lower edge of the cover plate, which is an anti-deflection boss. When the load-bearing frame slides downward, the sealing rubber is deformed upward due to friction, and the anti-deflection boss limits the deformation to prevent the load-bearing frame from deflecting.

[0031] A buffer is also provided on the outer edge of the steel lining. The buffer is located below the edge of the limiting steel beam and is fixed on the wall platform extending from the steel lining. The buffer includes an outer shell, an air spring, a fixed block and a slide. The air spring is fixed on the top of the wall platform and the outer shell covers the air spring. A slide is provided in the wall below the outer wall of the outer shell and the fixed block is fixed on the outside of the outer shell. When the upper limiting steel beam descends, the limiting steel beam is pressed on the top of the outer shell. After the outer shell is subjected to force, it slides into the slide and the internal air spring bears the pressure to provide buffering.

[0032] The usage of this energy storage system is as follows: 1. During periods of low electricity consumption, open the air inlet valve and close the air outlet valve. Air enters the air collecting shell through the connecting pipe and then evenly rushes into the air storage bag through the ventilation branch pipe connected to the circumference of the air collecting shell. As a large amount of gas rushes in, the air pressure in the air storage bag increases, slowly lifting the load-bearing frame and the gravity module on it. Under the action of the gravity module, the air volume is greatly compressed to form high-pressure gas. With the appropriate gravity module, the air pressure can reach 2MPa to 10MPa. 2. During peak hours of electricity consumption, the air inlet valve is closed and the air outlet valve is opened. Under the gravity of the gravity module, compressed air is discharged from the air outlet valve, and air energy is used to generate electricity.

[0033] During the compressed air process, when the load-bearing frame rises, the limiting steel beams and limiting blocks on the top of the steel frame cooperate to prevent the steel frame from falling off and causing accidents; when the load-bearing frame descends, the anti-deflection boss is used in conjunction with the bottom sealing strip to improve the stability of the load-bearing frame during sliding and the sealing performance of the stamping sealing structure; using an air bag as the air storage space, there is no need for a large number of modifications to the shaft, reducing the modification cost. At the same time, mass production of the air bag can reduce production costs, further reducing the use cost and maintenance cost of this energy storage system; designing the side wall of the air bag into an S-shaped fold can greatly reduce the volume of the air bag when not in use, making it easier to transport and store. During the inflation and deflation process, the rising and falling speed of the gravity module is 2m / s. At this slow descent speed, the air bag can be folded according to the folds. After long-term use, the folding effect of the air bag is reduced. Even if the air bag is no longer folded according to the folds, it will not affect the folding effect of the air bag. At the same time, the slow lifting and lowering speed causes less damage to the air bag, thereby increasing the service life of the air bag.

Claims

1. An airbag type gravity compressed air energy storage system, installed in a vertical shaft, characterized by The energy storage system includes a load-bearing frame, a gravity module, an air storage bag, and a gas balancing device. The load-bearing frame is horizontally arranged in a vertical shaft, dividing the shaft into upper and lower areas. The gravity module is placed on the load-bearing frame, and the air storage bag is placed in the area below the load-bearing frame. The gas balancing device is installed at the bottom of the vertical shaft and is connected to the bottom of the air storage bag. The load-bearing frame includes a pressure-bearing steel plate, a guide device, and a steel lining. The steel lining is vertically arranged on the inner wall of the shaft, and the pressure-bearing steel plate is horizontally arranged inside the shaft. Guide devices are symmetrically provided at both ends of the pressure-bearing steel plate. The guide devices are in contact with the steel lining, and the pressure-bearing steel plate slides along the steel lining through the guide devices. The edge of the airbag is S-shaped folded, with the top fixedly connected to the bottom of the carrier frame and the bottom fixedly connected to the bottom of the shaft. During transportation, the volume of the airbag is reduced to facilitate transportation; when gas is injected, the folds open to form the airbag wall; when gas is released, the outer wall of the airbag folds according to the folds; The gas balancing device includes a connecting pipe, an air inlet valve, an air outlet valve, a collecting ball shell and a ventilation branch pipe. The connecting pipe is horizontally arranged at the bottom of the vertical shaft. The air inlet valve and the air outlet valve are respectively installed at both ends of the connecting pipe, and the collecting ball shell is installed in the middle of the connecting pipe; several ventilation branches are installed on the collecting ball shell in a circular manner at one end, and the other end is connected to the bottom of the air storage bag. The collecting ball shell is connected to the air storage bag through the ventilation branch pipe.

2. The airbag type gravity compressed air energy storage system according to claim 1, characterized in that The gravity module includes a gravity block, a steel frame and a guide device. The steel frame is arranged on the upper part of the load-bearing frame. The gravity blocks are stacked sequentially in the steel frame. The array guide devices are installed on the outer wall of the steel frame from top to bottom. Each group of guide devices has at least two and is symmetrically arranged. The guide device is in contact with the steel lining, and the steel frame slides along the steel lining through the guide device.

3. The airbag type gravity compressed air energy storage system according to claim 2, characterized in that The top of the steel liner is provided with a limiting block and a limiting steel beam. The limiting steel beam is fixed on the top of the steel frame. The limiting block is arranged above the limiting steel beam to prevent the steel frame from sliding out and falling off, causing damage to the equipment.

4. The airbag type gravity compressed air energy storage system according to claim 1, characterized in that The guide device includes a frame, an elastic pad, a rotating frame, a guide wheel, a hinge shaft and a support. The frame is fixed to the pressure-bearing steel plate or the outer wall of the steel frame. The support and the elastic pad are respectively installed on both sides of the frame. One end of the rotating frame is fixed to the elastic pad by bolts, and the other end is connected to the support by a hinge shaft; the guide wheel is installed on the rotating frame, the outer edge of the guide wheel is higher than the outer edge of the rotating frame, and the outer edge of the guide wheel is in contact with the steel lining.

5. The airbag type gravity compressed air energy storage system according to claim 1, characterized in that Auxiliary sealing strips are also provided on both sides of the load-bearing frame. The auxiliary sealing strips include a base plate, a pressure plate, a sealing rubber, a retaining frame, a friction-reducing layer, a cavity and an anti-deflection boss. They are basically fixed on the bottom side wall of the load-bearing frame. The sealing rubber is L-shaped and an L-shaped retaining frame is buried inside. The vertical edge of the sealing rubber is fixed to the lower edge of the base plate, and the top of the horizontal edge is in contact with the steel lining. The top of the horizontal edge is plated with an anti-deflection layer; the cover plate covers the vertical edge of the sealing rubber and is basically connected and fixed; there is a cavity between the bending part of the sealing rubber and the cover plate, and the cavity provides storage space for the sealing rubber when it is deformed to prevent the sealing rubber from damaging the cover plate; a protrusion is provided at the lower edge of the cover plate, which is an anti-deflection boss.

6. The airbag type gravity compressed air energy storage system according to claim 1, characterized in that The outer edge of the steel lining is also provided with a buffer, which is located below the edge of the limiting steel beam and is fixed on the wall platform extending from the steel lining. The buffer includes an outer shell, an air spring, a fixed block and a slide groove. The air spring is fixed on the top of the wall platform, and the outer shell covers the air spring. A slide groove is provided in the wall below the outer wall of the outer shell, and the fixed block is fixed on the outside of the outer shell. When the upper limiting steel beam descends, the limiting steel beam is pressed on the top of the outer shell. After the outer shell is subjected to force, it slides into the slide groove, and the internal air spring bears the pressure to provide buffering.

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